• Journal of Magnetics
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• v.16 no.3
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• pp.318-321
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• 2011

A new Fe-based amorphous compound powder was prepared from Fe-Si-B amorphous powder by crushing amorphous ribbons as the first magnetic component and Fe-Cr-Mo metallic glassy powder by water atomization as the second magnetic component. Subsequently by adding organic and inorganic binders to the compound powder and cold pressing, the new Fe-based amorphous compound powder cores were fabricated. This new Fe-based amorphous compound powder cores combine the superior DC-Bias properties and the excellent core loss. The core loss of 500 kW/$m^3$ at $B_m$ = 0.1T and f = 100 kHz was obtained When the mass ratio of FeSiB/FeCrMo equals 3:2, and meanwhile the DC-bias properties of the new Fe-based amorphous compound powder cores just decreased by 10% compared with that of the FeSiB powder cores. In addition, with the increasing of the content of the FeCrMo metallic glassy powder, the core loss tends to decrease.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.581-587
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• 2003

This study was designed to examine the effect of icroencapsulated iron fortified drink yogurt and vitamin C as a bioavailable helper of iron on chemical and sensory aspects during 20 d storage. Coating material was polyglycerol monostearate (PGMS), and ferric ammonium sulfate and vit C were selected as core materials. The highest efficiency of microencapsulation of iron and vit C were 73% and 95%, respectively, with 5:1:50 ratio (w/w/v) as coating to core material to distilled water. Iron fortification did not affect the fermentation time required for the drink yogurt to reach pH 4.2. The addition of uncapsulated iron decreased the pH during storage. TBA absorbance was significantly lower in capsulated treatments than in uncapsulated treatments during storage. In sensory aspect, the yogurt sample added with uncapsulated iron and vit C, regardless of capsulation, showed a significantly high score of astringency, compared with those of control and other groups. A significantly strong sourness was observed in treatment containing capsulated iron and uncapsulated vitamin C at every time interval. The present study provides evidence that microencapsulation of iron with PGMS is effective for iron fortification in drink yogurt.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.415-423
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• 2008

Earth outer core is composed of iron mainly with some diluent elements, which account for the observed ca. 10% density deficit compared to the pure iron. Among candidates as the light diluents, hydrogen and oxygen were selected, and the thermodynamic stability of the following reaction was calculated; hematite + hydrogen $\to$ goethite + iron. At ambient conditions, Gibb's free energy of this reaction is 12.62 kJ/mol. On increasing pressure at room temperature, it decreases to zero at 0.068 GPa. This energy decreases at constant rate down to 200 GPa, which shows -208.26 kJ/mol at that pressure. From these results, this chemical reaction prefers the reduction environment forming the iron element and iron oxyhydroxide, so possible presence of iron oxyhydroxide with iron at proto-core can not be ruled out.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.115-121
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• 2008

This paper presents bisymmetric dual iron core lineal motor stage for heavy-duty high precision applications such as large area micro-grooving machines or high precision roll die machines. In this stage, two iron core linear motors are installed in laterally symmetric way to cancel out the attractive forces. Main focus was given to analyzing the effect of cogging force and moment for two different layouts, which are symmetric and half-pitch shifted ones. Experimental results showed that the symmetric layout is more adequate for high precision applications because of its clear moment cancellation effect. It was also verified that the effect of the residual cogging moment can be suppressed further by increasing the bearing stiffness. One problem of the symmetric layout is added cogging force which hinders smooth motion, but its effect was relatively small compared with that of moment cancellation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.601-604
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• 2003

The magnetic field generated in the iron core, which is required for the magnetic field to link each coil of the flux-lock type reactor, affects the fault current limiting characteristics of the flux-lock type high-Tc superconducting fault current limiter(SFCL). By applying numerical analysis for equivalent circuit of flux-lock type SFCL, the magnetic field induced in the iron core including currents of each coil was investigated. Through the analysis of magnetic field, we have analyzed that the magnetic field linked the 3rd coil, which is wound in the iron core, prevents the saturation of the iron core, but decreases the impedance of the flux-lock type SFCL.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.159-160
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• 2005

The superconducting fault current limiter(SFCLs) provides the effect such as enhancement in the power system reliability due to limiting fault current in a few miliseconds. The Flux-lock type SFCL using the YBCO film among various type SFCLs consists of the primary and the secondary copper coils that are wound in parallel each other through the iron core. The operation can be controlled by adjusting the inductances and the winging directions of each the coil. We compared the current limiting performance on the additive and the subtractive polarity winding directions in case of an open-loop iron core. To analyze quench characteristics, we experimented various phase angle.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.140-141
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• 2008

Generally, an iron-cored instrument transformer has differences between the primary current and the secondary current transformer due to the hysteresis characteristics of the core. The errors of the instrument transformer can be removed by using a compensating algorithm. This paper describes the iron-cored electronic zero-phase current transformer(EZCT) having a compensating algorithm that removes the effects of the hysteresis characteristics of the iron-core. This product composes an iron-cored ZCT and an intelligent electronic device(IED) ported the compensating algorithm. The test results shows that the innovative new product can improve the performance of the conventional ZCT.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1205-1211
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• 2003

This study was designed to examine the effect of microencapsulated iron-fortified Cheddar cheese and L-ascorbic acid as a bioavailable helper of iron on chemical and sensory aspects. Coating material was PGMS, and ferric ammonium sulfate and Lascorbic acid were selected as core materials. The highest efficiency of microencapsulation of iron and L-ascorbic acid were 72 and 94%, respectively, with 5:1:50 ratio (w/w/v) as coating to core material to distilled water. TBA absorbance was significantly lower in microencapsulated treatments than those in uncapsulated treatments during ripening. The productions of short-chain free fatty acid and neutral volatile compound were not significantly different among treatments during ripening periods. In sensory aspects, bitterness, astrigency and sourness were higher in Cheddar cheese fortified with microencapsulated iron and uncapsulated L-ascorbic acid than others. The present study indicated that fortification of iron as well as L-ascorbic acid did not show any defect problem to Cheddar cheese, and suggested the possibility of iron fortification of Cheddar cheese.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.165-166
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• 2014

The application of particle reaction model in the packed bed process modeling is discussed for iron ore pellet induration process. Combustion of coke breeze in the pellet is estimated by using shrinking unreacted-core model and grain model in which the progress of chemical reaction is described in different concepts. Under the identical inlet gas and solid conditions, the calculation using shrinking core model showed deviated results in terms of temperature profile and conversion fraction, which may imply the significance of selecting proper particle reaction model in consideration of particle characteristics and process operation conditions.

• Progress in Superconductivity and Cryogenics
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• v.20 no.1
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• pp.15-18
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• 2018

In this paper, the magnetizing characteristics of the current limiting reactor (CLR) using $high-T_C$ superconducting (HTSC) module were analyzed. Since the saturation of iron core comprising the CLR using HTSC module deteriorates its current limiting operation, the design of the CLR using HTSC module considering the magnetizing characteristics is needed. For the analysis on the magnetizing characteristics, the flux linkage and the magnetizing current of this CLR using HTSC module were derived from its electrical equivalent circuit. Through the analysis on the linkage flux versus the magnetizing current, obtained from the short-circuit tests, the suppressing effect of the iron core's saturation was discussed.